The present invention relates to a semiconductor design technology, and more particularly, to technology for generating an internal voltage by using an external power supply voltage.
Generally, semiconductor devices include an internal voltage generation circuit designed to generate a plurality of internal voltages by using an external power supply voltage in order to reduce power consumption and achieve efficient utilization of power.
When power is not stabilized. i.e., when the external power supply voltage starts to be supplied but does not reach a target voltage level, the internal voltages rise as a voltage level of the external power supply voltage rises. After the external power supply voltage that is supplied reaches the target voltage level, the internal voltages maintain a constant voltage level. Even though the external power supply voltage exceeds the target voltage level, the internal voltages are able to maintain the constant voltage level. When the external power supply voltage that is supplied reaches the target voltage level and thus the internal voltages are stabilized, the semiconductor device performs a reset operation and an internal operation.
Meanwhile, to improve the performance of the semiconductor device, the power supply voltage supplied to the semiconductor device may rise above the target voltage level. If the voltage level of the power supply voltage is increased for such an overclocking operation, the performance of the internal circuit using the increased power supply voltage is improved. However, the internal voltages generated from the internal voltage generation circuit of the semiconductor device maintain constant voltage levels even though the power supply voltage rises. Therefore, the performance of the internal circuits using the internal voltages as the operating voltages is not improved even though the power supply voltage rises.